The effect of safety modifications on head kinematics experienced during common skills in women's artistic gymnastics.

The objective of this study was to evaluate the effect of skill modifications on head motion experienced during women's artistic gymnastics skills. Nine gymnasts (four beginner and five advanced) completed three trials of up to 24 skill progressions, each consisting of a skill and two progressive safety modifications. Gymnasts were instrumented with mouthpiece sensors embedded with an accelerometer and gyroscope collecting motion data at 200, 300, and 500 Hz during each skill performance. Peak-to-peak linear and rotational kinematics during contact phases and peak rotational kinematics during non-contact phases were computed. A mixed-effects model was used to compare differences in modification status nested within skill categories. Timer skills (i.e. drills that simulate performance of a gymnastics skill) resulted in the highest median ΔLA and ΔRA of all skill categories, and 132 skill performances exceeded 10 g ΔLA during a contact phase. Modifications were associated with significant reductions in head kinematics during contact phases of timers, floor skills, bar releases, and vault skills. Gymnasts can be exposed to direct and indirect head accelerations at magnitudes consistent with other youth contact sports, and common safety modifications may be effective at reducing head motion during contact and non-contact phases of gymnastics skills.

Assessing Readiness for En Pointe in Young Ballet Dancers.

Children begin ballet lessons as young as age 2 years. The graceful movements of classical ballet require a combination of artistry, flexibility, and strength to perform. During the training and development of a young ballerina, the transition to dancing en pointe ("on the toes") represents a significant milestone and traditionally begins around age 11 or 12 years, assuming the proper training background and dance aspirations. However, current dance medicine literature describes factors such as maturity, proper technique, strength, and postural control as the more significant factors in determining pointe readiness. An in-office evaluation of these factors can be performed by the clinician to assist dancers, their family, and their dance instructor(s) determine pointe readiness.

Pathoanatomy of Anterior Ankle Impingement in Dancers.

Articles from the anatomy, orthopaedic, and radiology literature since 1943 were reviewed, and possible sources of anterior ankle impingement were identified therein. There are both osseous and soft tissue causes of impingement symptoms. Anterior impingement in dancers may be induced by repetitive dorsiflexion during demi-plié, where the anterior edge of the distal tibial articular surface contacts the dorsal neck of the talus. It also can be associated with the sequelae of lateral ankle sprain, including a hypertrophic tissue response, or simply by impingement of anatomically normal ligamentous structures. Dance medicine clinicians should be familiar with the pathoanatomy and etiologies of this clinical entity in order to provide effective care for dancers who suffer from it.

Is goniometry suitable for measuring ankle range of motion in female ballet dancers? An initial comparison with radiographic measurement.

UNLABELLED: Female ballet dancers require extreme ankle motion to attain the demi-plié (weight-bearing full dorsiflexion [DF]) and en pointe (weight-bearing full plantar flexion [PF]) positions of ballet. However, techniques for assessing this amount of motion have not yet received sufficient scientific scrutiny. Therefore, the purpose of this study was to examine possible differences between weight-bearing goniometric and radiographic ankle range of motion measurements in female ballet dancers. Ankle range of motion in 8 experienced female ballet dancers was assessed by goniometry and 2 radiographic measurement methods. The latter were performed on 3 mediolateral x-rays, in demi-plié, neutral, and en pointe positions; one of them used the same landmarks as goniometry. DF values were not significantly different among the methods, but PF values were (P < .05). Not only was PF of the talocrural joint significantly less than the other 2 measurements (P < .001), PF from the goniometric method applied to the x-rays was significantly less than PF obtained from clinical goniometry (P < .05). These data provide insight into the extreme ankle and foot motion, particularly PF, required in female ballet dancers and suggest that goniometry may not be ideal for assessing ankle range of motion in these individuals. Therefore, further research is needed to standardize how DF and PF are measured in ballet dancers. LEVEL OF EVIDENCE: Diagnostic, Level I.

Ankle and foot contributions to extreme plantar- and dorsiflexion in female ballet dancers.

BACKGROUND: Female ballet dancers require extreme ankle motion. The objective of this study was to quantify the relative contributions of the ankle and various foot joints to extreme plantarflexion (PF) and dorsiflexion (DF) in female ballet dancers using an X-ray superimposition technique and digital graphics software. MATERIALS AND METHODS: One asymptomatic ankle was studied in each of seven experienced female ballet dancers. Three lateral weightbearing X-rays were taken of each ballet dancer's ankle: en pointe (maximum PF), in neutral position, and in demi-plié (maximum DF). Using graphics software, a subject's three X-ray images were superimposed and the tali were aligned. On each image the tibia, navicular, intermediate cuneiform, and first metatarsal were marked. Positional differences of a bone's line among the three images demonstrated angular movement of the bone in degrees. The neutral position was the reference from which PF and DF of the bones were calculated. RESULTS: The talocrural joint contributed the most motion of any pair of bones evaluated for both PF and DF, with mean movements of 57.6 ± 5.2 degrees en pointe and 24.6 ± 9.6 degrees in demi-plié. Approximately 70% of total PF and DF were attributable to the talocrural joint, with the remaining 30% coming from motion between adjacent pairs of the studied foot bones. CONCLUSION: Superimposed X-rays for assessing ankle and foot contributions to the extreme positions required of female ballet dancers offer insight into how these positions are attained that is not available via goniometry. CLINICAL RELEVANCE: Functional information gained from this study may assist clinicians in assessing ankle and foot pain in these individuals.

Pathoanatomy of posterior ankle impingement in ballet dancers.

Dance is a high performance athletic activity that leads to great numbers of injuries, particularly in the ankle region. One reason for this is the extreme range of ankle motion required of dancers, especially females in classical ballet where the en pointe and demi-pointe positions are common. These positions of maximal plantar flexion produce excessive force on the posterior ankle and may result in impingement, pain, and disability. Os trigonum and protruding lateral talar process are two common and well-documented morphological variations associated with posterior ankle impingement in ballet dancers. Other less well-known conditions, of both bony and soft tissue origins, can also elicit symptoms. This article reviews the anatomical causes of posterior ankle impingement that commonly affect ballet dancers with a view to equipping healthcare professionals for improved effectiveness in diagnosing and treating this pathology in a unique type of athlete.

Measurement of the extreme ankle range of motion required by female ballet dancers.

Female ballet dancers require extreme ankle motion, especially plantar flexion, but research about measuring such motion is lacking. The purposes of this study were to determine in a sample of ballet dancers whether non-weight-bearing ankle range of motion is significantly different from the weight-bearing equivalent and whether inclinometric plantar flexion measurement is a suitable substitute for standard plantar flexion goniometry. Fifteen female ballet dancers (5 university, 5 vocational, and 5 professional dancers; age 21 ± 3.0 years) volunteered. Subjects received 5 assessments on 1 ankle: non-weight-bearing goniometry dorsiflexion (NDF) and plantar flexion (NPF), weight-bearing goniometry in the ballet positions demi-plié (WDF) and en pointe (WPF), and non-weight-bearing plantar flexion inclinometry (IPF). Mean NDF was significantly lower than WDF (17° ± 1.3° vs 30° ± 1.8°, P < .001). NPF (77° ± 2.5°) was significantly lower than both WPF (83° ± 2.2°, P = .01) and IPF (89° ± 1.6°, P < .001), and WPF was significantly lower than IPF (P = .013). Dorsiflexion tended to decrease and plantar flexion tended to increase with increasing ballet proficiency. The authors conclude that assessment of extreme ankle motion in female ballet dancers is challenging, and goniometry and inclinometry appear to measure plantar flexion differently.

Magnetic resonance imaging of the ankle in female ballet dancers en pointe.

BACKGROUND: Ballet dancers require extreme range of motion of the ankle, especially weight-bearing maximum plantar flexion (en pointe). In spite of a high prevalence of foot and ankle injuries in ballet dancers, the anatomy and pathoanatomy of this position have not been sufficiently studied in weight-bearing. Magnetic resonance imaging (MRI) is a beneficial method for such study. PURPOSE: To develop an MRI method of evaluating the ankles of female ballet dancers standing en pointe and to assess whether pathological findings from the MR images were associated with ankle pain reported by the subjects. MATERIAL AND METHODS: Nine female ballet dancers (age, 21+/-2.9 years; dance experience, 16+/-4.1 years; en pointe dance experience, 7+/-4.9 years) completed an ankle pain visual analog scale questionnaire and underwent T1- and T2-weighted scans using a 0.25 T open MRI device. The ankle was scanned in three positions: supine with full plantar flexion, standing with the ankle in anatomical position, and standing en pointe. RESULTS: Obtaining MR images of the ballet dancers en pointe was successful in spite of limitations imposed by the difficulty of remaining motionless in the en pointe position during scanning. MRI signs of ankle pathology and anatomical variants were observed. Convergence of the posterior edge of the tibial plafond, posterior talus, and superior calcaneus was noted in 100% of cases. Widened anterior joint congruity and synovitis/joint effusion were present in 71% and 67%, respectively. Anterior tibial and/or talar spurs and Stieda's process were each seen in 44%. However, clinical signs did not always correlate with pain reported by the subjects. CONCLUSION: This study successfully established an ankle imaging technique for ballet dancers en pointe that can be used in the future to assess the relationship between en pointe positioning and ankle pathoanatomy in ballet dancers.

Intraarticular cortisone injection for osteoarthritis of the hip. Is it effective? Is it safe?

Osteoarthritis of the hip is a significant source of morbidity in the elderly. Treatment guidelines are available for the management of hip osteoarthritis, but these do not address the application of intraarticular corticosteroid injection. The intraarticular injection of corticosteroid is used in the management of other large joint osteoarthritic diseases and is well studied in the knee, however, this data cannot be used to make sound clinical decisions regarding its use for hip osteoarthritis. There are also concerns regarding the safety of this modality. Review of the published literature reveals that there are eight trials examining the efficacy of intraarticular corticosteroid injection for hip osteoarthritis and of these only four are randomized controlled trials. In general, the available literature demonstrates a short-term reduction of pain with corticosteroid injection and is indicated for patients refractory to non-pharmacologic or analgesic and NSAID therapy. The use of radiologic-guidance is recommended and, with proper sterile technique, the risk of adverse outcomes is very low. Future randomized controlled trials are needed to further examine the efficacy and safety of intraarticular corticosteroid injection for hip osteoarthritis.